Obviously, it would be QB1—the more accurate, efficient, and productive quarterback. Fortunately for the Denver Broncos, QB1 represents Peyton Manning, starting for them this weekend in the AFC Championship against the New England Patriots. Unfortunately for the Broncos, they will also be starting QB2 … Peyton Manning. The stats above display the statistical career splits for Manning in the regular season and postseason, respectively, illustrating a juxtaposition that is difficult to ignore.

Manning, for better or worse, will go down in sports history as the greatest regular-season quarterback of all-time. Let’s take a look at the numbers to explain why (again, per pro-football-reference.com):

Peyton’s lucky number is 13 when it comes to breaking NFL records. All league-leading marks,13 is the number of Pro Bowls to which Manning has been named, seasons with 10 or more victories, seasons with at least 4,000 passing yards, and consecutive seasons with at least 25 touchdown passes.

He has won the league MVP award a record four times, likely with a fifth on the way. He has won 167 regular-season games, second only to Brett Favre with 186, a total he will likely pass if he can start two (or likely even one and a half) more seasons. And while he has fewer wins than Favre, he also has significantly fewer losses (42), bestowing him with the highest winning-percentage for a quarterback that has over 200 starts (69.6%).

As we all know, Manning also just completed what most contend to be the greatest regular season ever by a quarterback, including record-breaking numbers for touchdown passes (55) and passing yards (5,477).

… and the list goes on and on. He holds the largest career touchdown to interception differential (272), the most games with at least 300 passing yards (84), the most games with a perfect passer rating (3) ... you get the idea. No one is surpassing Manning’s regular-season dominance anytime soon, if ever.

Earning the title of “greatest regular-season quarterback of all-time” should be something on which Manning can hang his helmet, however, his postseason career has instead muddled this brilliant legacy with a cacophony of criticism that only grows louder as his regular-season numbers grow gaudier.

Again, let’s take a look at Manning’s career numbers, this time for the postseason:

Manning has the most postseason appearances of any quarterback (lucky 13!), which should be considered a positive stat until you realize he also is tied with Brett Favre for the most playoff losses (11) and holds the record for most first-round postseason losses (8). Eight! Eight out of the 13 times that Manning has brought his team to the postseason, they’ve never advanced a single round.

It is hard to disregard this extreme contrast of all-time success and all-time failure. While Manning also holds many positive postseason records (such as leading the biggest comeback in conference championship history against New England in 2007), the numbers bulleted above stand out along with one other number: 1, the number of Super Bowl rings on his fingers. All the MVPs and Pro Bowls in the world will not be fully appreciated until that particular number (at least) doubles.

Is it all too serendipitous that, at this point in his career, Peyton Manning has found himself playing for the Denver Broncos, a team whose other legendary quarterback had his fair share of tremendous regular-season success combined with consistent postseason disappointment? Before John Elway, Manning’s current boss, won his first Super Bowl, he had won more regular-season games than any quarterback in NFL history. Then, after winning back-to-back titles at ages 37 and 38 (by the way, Peyton’s age is currently 37), Elway is viewed by most today as one of the greatest (if not the greatest) quarterbacks in NFL history.

As fair or unfair as it may be, if this were Manning’s final season, the difference between winning these next two games versus losing this weekend would almost certainly define two very disparate legacies. After having just completed the most historic regular-season performance ever by the greatest regular-season quarterback ever, falling short of a Super Bowl this year would only magnify the disparity.

Adding potential insult to potential injury, there’s no worse team in the league for Manning to lose to this weekend than the one led by the other legendary quarterback of this generation, whose postseason distinction is essentially the opposite of Manning’s. Making a strong argument to be considered as the greatest postseason quarterback of all time, Tom Brady has three Super Bowl trophies to his name (one less than the record, four, held by Joe Montana and Terry Bradshaw), he is tied with Elway for the most Super Bowl appearances by a quarterback (5), and his 18 playoff victories and 25 games started are the most by any quarterback in NFL history.

Losing again to Brady and sending him to a record sixth Super Bowl would cement the separation between the two titans of today’s game. On the other hand, if Manning can pull out a victory, there’s also no better team for him to defeat in terms of legacy-bolstering implications. The outcome of Manning-Brady XV (as well as the ensuing Super Bowl XLVIII) is clearly monumental for Manning; another ring would elevate him into the conversation of the Mount Rushmore of quarterbacks with Elway, Brady, and Montana, while a loss would exacerbate his narrative of historic postseason failure. The history book-keepers will be watching on Sunday with bated breath.